Disclosure provides a formulation of curcuminoid with essential oil of turmeric to enhance the bioavailability of curcumin and to augment the biological activity of curcumin, wherein curcumin is the main constituent of curcuminoid and wherein Ar-turmerone is the main constituent of the essential oil of turmeric. An application of curcuminoid with essential oil of turmeric to enhance the bioavailability of curcumin for oral supplementation against a variety of diseases and method of doing the same is provided.